Add time synchronization with callback example. (#131)

CMakeLists.txt

@@ -294,6 +294,7 @@ if(UCLIENT_BUILD_EXAMPLES)
     add_subdirectory(examples/Deployment)
     add_subdirectory(examples/Discovery)
     add_subdirectory(examples/TimeSync)
+    add_subdirectory(examples/TimeSyncWithCb)
 endif()
 
 ###############################################################################

examples/TimeSyncWithCb/CMakeLists.txt

@@ -0,0 +1,51 @@
+# Copyright 2017-present Proyectos y Sistemas de Mantenimiento SL (eProsima).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cmake_minimum_required(VERSION 2.8.12)
+if (${CMAKE_VERSION} VERSION_GREATER 3.0)
+    cmake_policy(SET CMP0048 NEW)
+endif()
+
+project(time-sync-with-cb)
+
+if(NOT UCLIENT_BUILD_EXAMPLES)
+    find_package(microxrcedds_client REQUIRED)
+endif()
+
+if(NOT PROFILE_UDP_TRANSPORT)
+    message(WARNING "Can not compile example: The PROFILE_UDP_TRANSPORT must be enabled.")
+else()
+    add_executable(${PROJECT_NAME} main.c)
+    if(MSVC OR MSVC_IDE)
+        target_compile_options(${PROJECT_NAME} PRIVATE /wd4996)
+    endif()
+
+    set_target_properties(${PROJECT_NAME} PROPERTIES
+        C_STANDARD 99
+        C_STANDARD_REQUIRED YES
+        )
+
+    target_link_libraries(${PROJECT_NAME} microxrcedds_client $<$<C_COMPILER_ID:GNU>:-Wl,--gc-section,--no-export-dynamic>)
+
+    install(TARGETS ${PROJECT_NAME}
+        RUNTIME DESTINATION examples/uxr/client/${PROJECT_NAME}/${BIN_INSTALL_DIR}
+        )
+
+    install(DIRECTORY ${PROJECT_SOURCE_DIR}/
+        DESTINATION  examples/uxr/client/${PROJECT_NAME}
+        FILES_MATCHING PATTERN "*.h"
+                       PATTERN "*.c"
+                       PATTERN "*.idl"
+        )
+endif()

examples/TimeSyncWithCb/main.c

@@ -0,0 +1,97 @@
+// Copyright 2017-present Proyectos y Sistemas de Mantenimiento SL (eProsima).
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <uxr/client/client.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#ifdef WIN32
+#include <windows.h>
+#else
+#include <unistd.h>
+#endif
+
+int64_t avg_time_offset = 0;
+size_t sample_id = 0;
+
+void on_time(
+        uxrSession* session,
+        int64_t current_time,
+        int64_t transmit_timestamp,
+        int64_t received_timestamp,
+        int64_t originate_timestamp,
+        void* args)
+{
+    (void) args;
+    int64_t current_time_offset = ((current_time - originate_timestamp) - (transmit_timestamp - received_timestamp)) / 2;
+    avg_time_offset = (avg_time_offset * sample_id + current_time_offset) / (sample_id + 1);
+    ++sample_id;
+    session->time_offset = avg_time_offset;
+}
+
+int main(int args, char** argv)
+{
+    // CLI
+    if(3 > args || 0 == atoi(argv[2]))
+    {
+        printf("usage: program [-h | --help] | ip port\n");
+        return 0;
+    }
+
+    char* ip = argv[1];
+    uint16_t port = (uint16_t)atoi(argv[2]);
+
+    // Transport
+    uxrUDPTransport transport;
+    uxrUDPPlatform udp_platform;
+    if(!uxr_init_udp_transport(&transport, &udp_platform, ip, port))
+    {
+        printf("Error at create transport.\n");
+        return 1;
+    }
+
+    // Session
+    uxrSession session;
+    uxr_init_session(&session, &transport.comm, 0xCCCCDDDD);
+    if(!uxr_create_session(&session))
+    {
+        printf("Error at create session.\n");
+        return 1;
+    }
+
+    // Set time-callback.
+    uxr_set_time_callback(&session, on_time, NULL);
+
+    // Synchronize with the Agent
+    bool synchronized = false;
+    do
+    {
+        synchronized = uxr_sync_session(&session, 1000);
+#ifdef WIN32
+        printf("synchronized with time offset %-5I64d us\n", session.time_offset / 1000);
+        Sleep(1);
+#else
+        printf("synchronized with time offset %-5" PRId64 "us\n", session.time_offset / 1000);
+        sleep(1);
+#endif
+
+    } while (synchronized);
+
+    // Delete resources
+    uxr_delete_session(&session);
+    uxr_close_udp_transport(&transport);
+
+    return 0;
+}